The network’s founding chairman, Roger E. Ailes, died on Thursday, sending a shock through a newsroom still reeling from a string of harassment scandals, lawsuits and high-profile departures. The threat of a federal investigation into the network’s financial practices has lingered.

And on Friday, another prominent on-air personality was abruptly tossed. Bob Beckel, a co-host of the prime-time talk show “The Five,” was fired after an African-American employee accused him of making a racially insensitive remark.

The drumbeat of tough headlines has taken a toll on morale at Fox News, with employees on and off camera describing a feeling of being under siege.

And after years as the undisputed king of cable news, Fox News ranked third in prime-time this week among the 25-54 age group most important to advertisers, finishing behind its rivals MSNBC and CNN. In total audience, MSNBC edged out Fox News in prime-time on three nights, an unsettling sign for an evening schedule scrambled by last month’s exit of Bill O’Reilly.

Including daytime hours, Fox News remains first in total audience; last week, it notched its 19th consecutive weekly ratings win. But amid a series of damaging news reports this week about President Trump, the conservative network’s hosts stirred some skepticism among media commentators by instead airing stories about the Clintons’ charitable foundation — the Fox News equivalent of a greatest hits reel.

The exit of Mr. Beckel — one of the channel’s few left-leaning commentators, and known for his signature suspenders — also refocused attention on whether Fox News’s workplace culture had changed after the departures of Mr. Ailes and Mr. O’Reilly.

Mr. Beckel was accused of walking out of his office this week after an African-American network employee arrived to service his computer. Mr. Beckel said that he was leaving because the employee was black, according to the employee’s lawyer, Douglas H. Wigdor.

Mr. Wigdor, who represents 13 Fox News employees in a class-action racial discrimination suit against the network, said Mr. Beckel tried to persuade his client to withdraw the complaint during a meeting with Fox News’s new executive vice president for human resources, Kevin Lord.

Fox News disputed that account — and portrayed the episode as an example of its newly rapid response to internal problems.

“No one tried to persuade Mr. Wigdor’s client to withdraw his complaint,” the network said in a statement, noting that Mr. Lord responded to the employee’s complaint within seven minutes of receiving it. Mr. Beckel, who did not respond to requests for comment, apologized to the employee on Friday shortly after learning of his dismissal.

Mr. Wigdor’s firm also represents plaintiffs in a racial discrimination suit against The New York Times.

Along with Mr. Lord, the network has hired executives for its human resources team and has strengthened sensitivity training requirements.

This is not Mr. Beckel’s first acrimonious departure from Fox News: He was dismissed from “The Five’’ in 2015, but was welcomed back earlier this year. The network’s executive chairman, Rupert Murdoch, offered Mr. Beckel a warm reception upon his return.

Mr. Ailes’s death, caused by complications from a fall last week at his home in Palm Beach, Fla., was a jarring reminder of how much has changed in the past 10 months at the network. Anchors offered teary on-air tributes to him throughout the day on Thursday, some acknowledging his flaws, while hailing his skills and vision as a broadcaster.

“He left the company and the rest is history still unfolding,” the anchor Shepard Smith said in a deeply personal monologue. “To the true victims, respect and comfort. It’s all so complicated. Everything here was and is. As he was.”

Some employees, however, say privately that they are unsettled by the power retained by former Ailes lieutenants, including Dianne Brandi, the general counsel, and Suzanne Scott, who was recently promoted to the chief of programming.

A day after the death of Mr. Ailes, the fate of the federal investigation into him and the news network he founded remained unclear.

The inquiry, which began in September, has appeared to focus in part on how settlements at the network were paid and accounted for. Two people familiar with the matter said they were given signals after news broke that Mr. Ailes had died that the investigation was proceeding, although another person said it remained to be seen how its scope and target could change. It is possible the investigation could be put on hold.

Other matters raised in the course of the investigation include how Mr. Ailes conducted business at the network; a New York Times investigation that revealed multiple settlements tied to harassment allegations against Mr. O’Reilly; and the assertions made in recent lawsuits filed against Fox News and Mr. Ailes, two people briefed on the matter said.

Investigators have talked with current and former Fox News employees, including Mark Kranz, the network’s former chief financial officer, and Brian Lewis, its former public relations chief. Both Mr. Kranz and Mr. Lewis were subpoenaed and granted immunity, according to people familiar with the matter.

Legal experts said that, should the investigation continue, the focus would likely shift to the network and its parent company, 21st Century Fox, which could be held liable for Mr. Ailes’s conduct.

“It will not give the company a free pass even if they want to say, ‘Well, Ailes never told us,’” said Peter J. Henning, a professor at Wayne State University Law School in Detroit. “Well, too bad. It doesn’t matter if the executive lied to senior management. It is the company’s books and records, and those have to be accurate.”

Daniel C. Richman, a former federal prosecutor and currently a professor at Columbia Law School, said Mr. Ailes’s death removes a potential target and increases the likelihood that he could be blamed for wrongdoing. But, Mr. Richman added, “You have a number of possibilities that the government can continue looking at.”

Earlier this month, 21st Century Fox disclosed in a regulatory filing that the company had “received regulatory and investigative inquiries” relating to allegations of misconduct at Fox News. In February, Fox News said in a statement that it had been in communication with the United States attorney’s office in Manhattan and would “continue to cooperate on all inquiries with any interested authorities.”

The death of Mr. Ailes also complicates the multiple lawsuits filed against him and the network.

In April, Julie Roginsky, a current Fox News contributor, filed a lawsuit asserting that she faced retaliation for rebuffing Mr. Ailes’s sexual advances and for refusing to disparage Gretchen Carlson, the former anchor who sued Mr. Ailes last summer. Ms. Roginsky’s lawyer, Nancy Erika Smith, said her client planned to add the estate of Mr. Ailes as a defendant in the case.

Andrea Tantaros, a former Fox News host, has named Mr. Ailes in two lawsuits. Judd Burstein, a lawyer for Ms. Tantaros, declined to comment as to whether Ms. Tantaros would amend her complaints.

Ben Protess and William K. Rashbaum contributed reporting.

A version of this article appears in print on , on Page B1 of the New York edition with the headline: Fox News Fires Another Host, as Tough Headlines Keep the Staff Reeling. Order Reprints | Today’s Paper | Subscribe